Merge branch 'main' into concurrency-improvements

.gitignore

@@ -2,4 +2,4 @@
 docker-compose.yml
 .DS_Store
 *bin
-/tmp
+/tmp

main.go

@@ -50,8 +50,6 @@ func main() {
 	r.GET("/", routes.GetHome)
 	r.POST("/", routes.PostHome)
 
-	r.GET("/a/:id", routes.RedirectShortenedOverflowURL)
-
 	r.GET("/questions/:id", func(c *gin.Context) {
 		// redirect user to the question with the title
 		c.Redirect(302, fmt.Sprintf("/questions/%s/placeholder", c.Param("id")))

src/routes/home.go

@@ -35,14 +35,10 @@ func PostHome(c *gin.Context) {
 
 	soLink := body.URL
 
-	// remove the www.
-	soLink = strings.ReplaceAll(soLink, "www.", "")
-
 	// validate URL
 	isStackOverflow := strings.HasPrefix(soLink, "https://stackoverflow.com/questions/")
-	isShortenedStackOverflow := strings.HasPrefix(soLink, "https://stackoverflow.com/a/")
 	isStackExchange := stackExchangeRegex.MatchString(soLink)
-	if !isStackExchange && !isStackOverflow && !isShortenedStackOverflow {
+	if !isStackExchange && !isStackOverflow {
 		c.HTML(400, "home.html", gin.H{
 			"errorMessage": "Invalid stack overflow/exchange URL",
 			"theme":        c.MustGet("theme").(string),
@@ -51,7 +47,7 @@ func PostHome(c *gin.Context) {
 	}
 
 	// if stack overflow, trim https://stackoverflow.com
-	if isStackOverflow || isShortenedStackOverflow {
+	if isStackOverflow {
 		c.Redirect(302, strings.TrimPrefix(soLink, "https://stackoverflow.com"))
 		return
 	}

src/routes/shortened.go

@@ -1,44 +0,0 @@
-package routes
-
-import (
-	"fmt"
-	"net/http"
-	"os"
-
-	"github.com/gin-gonic/gin"
-	"github.com/go-resty/resty/v2"
-)
-
-func RedirectShortenedOverflowURL(c *gin.Context) {
-	id := c.Param("id")
-
-	// fetch the stack overflow URL
-	client := resty.New()
-	client.SetRedirectPolicy(
-		resty.RedirectPolicyFunc(func(req *http.Request, via []*http.Request) error {
-			return http.ErrUseLastResponse
-		}),
-	)
-
-	resp, err := client.R().Get(fmt.Sprintf("https://www.stackoverflow.com/a/%s", id))
-	if err != nil {
-		c.HTML(400, "home.html", gin.H{
-			"errorMessage": "Unable to fetch stack overflow URL",
-			"theme":        c.MustGet("theme").(string),
-		})
-		return
-	}
-
-	if resp.StatusCode() != 302 {
-		c.HTML(400, "home.html", gin.H{
-			"errorMessage": fmt.Sprintf("Unexpected HTTP status from origin: %d", resp.StatusCode()),
-			"theme":        c.MustGet("theme").(string),
-		})
-		return
-	}
-
-	// get the redirect URL
-	location := resp.Header().Get("Location")
-
-	c.Redirect(302, fmt.Sprintf("%s%s", os.Getenv("APP_URL"), location))
-}

src/utils/images.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"regexp"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/golang-jwt/jwt/v4"
@@ -14,20 +15,28 @@ import (
 var imgTagRegex = regexp.MustCompile(`<img[^>]*\s+src\s*=\s*"(.*?)"[^>]*>`)
 
 func ReplaceImgTags(inHtml string) string {
-	// find all img tags
 	imgTags := imgTagRegex.FindAllString(inHtml, -1)
 
+	var wg sync.WaitGroup
+	var mu sync.Mutex
+
 	for _, imgTag := range imgTags {
-		// parse the src="" attribute
-		srcRegex := regexp.MustCompile(`src\s*=\s*"(.*?)"`)
-		src := srcRegex.FindStringSubmatch(imgTag)[1]
+		wg.Add(1)
+		go func(imgTag string) {
+			defer wg.Done()
+			srcRegex := regexp.MustCompile(`src\s*=\s*"(.*?)"`)
+			src := srcRegex.FindStringSubmatch(imgTag)[1]
 
-		authToken, _ := generateImageProxyAuth(src)
+			authToken, _ := generateImageProxyAuth(src)
 
-		// replace the img tag with a proxied url
-		inHtml = strings.Replace(inHtml, imgTag, fmt.Sprintf(`<img src="%s/proxy?auth=%s">`, os.Getenv("APP_URL"), authToken), 1)
+			mu.Lock()
+			defer mu.Unlock()
+			inHtml = strings.Replace(inHtml, imgTag, fmt.Sprintf(`<img src="%s/proxy?auth=%s">`, os.Getenv("APP_URL"), authToken), 1)
+		}(imgTag)
 	}
 
+	wg.Wait()
+
 	return inHtml
 }